Efficacy of SALI-10 Oral Probiotics in Experimental Gingivitis

Gingivitis is among the most prevalent oral diseases worldwide, affecting an estimated 50-90% of adults. It is a reversible condition primarily caused by microbial plaque accumulation on teeth and gingival surfaces, which triggers inflammation. Standard care emphasizes plaque reduction through oral hygiene, and research shows gingivitis can be reversed once hygiene resumes. The classic experimental gingivitis (EG) model developed in 1965 by Löe and Silness demonstrated the direct link between plaque buildup and gingival inflammation, further confirming that gingival health can be restored after resuming proper care.

Microbial ecology shifts are central to gingivitis pathogenesis. In health, the oral microbiome is dominated by gram-positive Streptococcus species. With plaque accumulation, microbial communities transition to gram-negative periopathogens such as Porphyromonas, Tannerella, Treponema, and Prevotella. This dysbiosis provokes heightened inflammation, tissue damage, and, in susceptible individuals, progression to periodontitis. Individual variability in the inflammatory response has been associated with differences in the presence and activity of beneficial streptococci. Certain strains of Streptococcus salivarius produce lantibiotics called salivaricins-polycyclic antimicrobial peptides containing lanthionine residues. Salivaricins inhibit oral pathogens and have been investigated for their antimicrobial and probiotic properties, particularly in the context of rising antibiotic resistance. Probiotic S. salivarius strains isolated from healthy individuals have demonstrated safety and antimicrobial potential in previous studies, supporting their use in preventing oral and respiratory infections.

A strain of S. salivarius designated SALI-10 produces a lantibiotic, Salivaricin 10, and is being evaluated as a candidate for gingivitis prevention. This strain is hypothesized to (1) help stabilize populations of beneficial streptococci during plaque accumulation, (2) competitively inhibit periopathogens such as Porphyromonas and Prevotella, and (3) suppress the dysbiotic shift toward gram-negative dominance. By contributing to microbial balance and reducing inflammatory triggers, SALI-10 may support resilient host-microbe interactions associated with gingival health. This approach may offer a dual antimicrobial and microbiome-stabilizing strategy with relevance to gingivitis management and longer-term periodontal health.